Electrical pushbutton type switches



July 9, 1968 D. RUSHTON ELECTRICAL PUSHBUTTON TYPE SWITCHES 4Sheets-Sheet 1 Filed Feb. 7, 1966 y 1968 D. RUSHTON 3,392,251

ELECTRICAL PUSHBUTTON TYPE SWITCHES Filed Feb. 7, 1966 4 Sheets-Sheet 2l I A. I...

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ELECTRICAL PUSHBUTTON TYPE SWITCHES Filed Feb. 7, 1966 4 Sheets-Sheet 5/k 1a 12 fl' j fl 10 D. RUSHTON ELECTRICAL PUSHBUTTON TYPE SWITCHES July9, 1968 4 Sheets-Sheet 4 Filed Feb. 7, 1966 United States Patent3,392,251 ELECTRICAL PUSHBUTTON TYPE SWITCHES Derek Rushton, Accrington,England, assignor to Joseph Lucas (Industries) Limited, Birmingham,England, a

British company Filed Feb. 7, 1966, Scr. No. 525,677 2 Claims. (Cl.200-459) ABSTRACT OF THE DISCLOSURE An electrical switch comprising apushbutton controlling the movem ent of an operating element, movementof the pushbutton causing travel of the operating element in arelatively transverse direction such movement being controlled by a pinand track on the pushbutton arm and operating element respectively, andthe track having two positions for the pin in which it can be releasabiyretained, the operating element carrying a contact plate which ismovable transversely of the direction of the movement of the pushbuttonbetween a position to engage a contact on a printed circuit board, and afurther position spaced from such contact.

This invention relates to electrical switches of the kind movablebetween on and oil positions in response to manual pressure upon aresiliently biased push button.

The object of the invention is to provide a convenient form of such aswitch.

According to the present invention an electrical switch of the kindspecified comprises a pair of members comprising an arm and an operatingelement which are each slidably mounted so as to be movable in mutuallytransverse directions, one of said members having a pin which isengageable in a track provided on the other member, the track being soarranged that movement of said arm will result in transverse movement ofsaid operating element between two limiting positions relative to thearm, said track being shaped to provide two positions corresponding tosaid limiting positions of the operating element in which the pin isreleasably retained by the track, said arm being connected to the pushbutton so as to be movable in one direction by said push button andresilient means being provided for moving the arm in the oppositedirection, and the pin being movable from either of said positions tothe other by a sliding motion of the arm which consists in part ofmovement imparted by said push button and in part of movement impartedby said resilient means, the operating element being operativelyconnected to a contact plate adapted, in said limiting positions of theoperating element, respectively electrically to connect and separateelectrical contacts.

The invention will now be described by way of example with reference tothe accompanying drawings in which:

FIGURE 1 is a cross-sectional side elevation view of the switch,

FIGURE 2 is a view on the line IIII in FIGURE 1,

FIGURE 3 is a similar view to FIGURE 2 but showing the parts in a switchon position, and

FIGURE 4 is a view on the line IV-IV in FIGURE 2.

In this example the switch comprises a body arranged to be secured to apanel by means of an attachment flange 11. The body is of hollow boxlike form and has openings in opposite end walls which serve as guidesfor an arm 12, one end of which extends out of the body and has anintegral or a separate push button 13. One of the end walls is formed bya detachable closure member 14 secured to the remainder of the .body bytwo screws 15.

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The end walls of the body 10 also guide an operating element 16 in theform of a block-like member slidable in a direction transversely to thedirection of movement of the arm 12.

The body 10 has, at its end remote from that from which the arm extends,an integral closed ended channel shaped extension 17. This extension ofthe body contains a compression spring 18 which abuts against the closedend of the channel and, at its other end, against the inner end of arecess in the arm 12, this spring urging the arm towards its outerposition, shown in FIGURES 1, 2 and 3. A spigot 19 is formed on the endof the channel to locate the spring laterally.

The arm 12 has a laterally extending blind bore 20 which contains a pin21 loaded by a compression spring 22, the pin 21 having a rounded nosenormally protruding from the bore 20, but this pin 21 is capable ofbeing retract'ed wholly within the bore 20, against the action of thespring 22. The operating element 16 has an integral peg 23 forengagement by one end of a compression spring 24 which urges theoperating element 16 towards one side of the housing 10. The oppositeend of the spring 24 is located on a peg 25 formed on an extension ofthe closure member 14. The operating element 16 has an integral bridgeportion 26, which joins the operating element to a contact carrier 27.This contact carrier extends through one of the openings in the end wallof the body beside the extension 17 of the body.

In a face of the operating element 16 presented to the arm 12, there isprovided a track 23 in the form of a channel cross-section groove inwhich the pin 21 is located. The track is a generally triangular closedloop. A first side 28a of the track is inclined at approximately to thedirection of movement of the arm 12 and a second side 28b has a U-shapedportion intermediate its ends, the U extending towards the middle of thetriangle.

The third side 28c is inclined to the direction of movement of the arm12 at an angle of only approximately 5, the base of the third sideincluding means for preventing movement from the first to the third sidein the form of a ramp seen in FIGURE 1 occupying those parts of the sidebetween the junctions with the other two sides, that is excluding theportions of the groove common to the first and third and second andthird sides respectively. The maximum height of the ramp isapproximately equal to the depth of the track 28 and the portion maximumheight is adjacent to the junction between the first and third sides.

The contact carrier 27 is in the form of a rectangular block having ablind bore 29 in its end remote from the bridge portion 26 to house aspring 30 which bears against a metal contact plate 31 of generally Ucross-section which is held for limited relative sliding movementagainst the sides of the contact carrier 27, towards and away from theoperating element, by engagement of integral projections 32 on thecontact carrier in openings formed in the walls of the contact plate 31.The contact plate 31 has two, or possibly more, integral contactprojections which are engageable with side-by-side conducting strips ona printed circuit board B adjacent to which the switch is supported. Itwill be become apparent from the following description of the operationof the switch that the contact carrier 27 is slidable across the face ofthe board B between positions in which the strips are alternatively inelectrical contact through the contact plate 31, or are separated fromone another. Conveniently all the parts, with the exception of thesprings and pin 21 and Contact piece 31 are formed from syntheticresinous materials.

In describing the mode of operation of the switch, the parts must beconsidered to be in an initial position (shown in FIGURES 1, 2 and 4) inwhich the push" button 13 and arm 12 are held by the spring 18 in anoutermost position and the pin 21 carried by the arm 12 is held in thetrack 28 at the junction of the first side 28a and the third side 28c.The operating element 16 is held in a position equivalent to that inwhich the contact plate 31 on the contact carrier 27 would be out ofcontact with the strips on the member.

When the push button 13 is actuated to move the switch to the onposition, the arm 12, carrying the pin 21, moves along the firstinclined side 28a of the track 28, this movement of the pin 21 causingthe operating element to move against the action of its spring 24transversely to the direction of movement of the arm 12. When the pushbutton 13 is released, the spring 18 tends to return the push button tothe outermost position but the spring 24 of the operating element causestransverse movement of that element such movement being limited by theportion of the wall of the track constituting the inside of the U of thesecond side 28b, this portion of course being normal to the direction ofmovement of the operating element under the action of the Spring 24. Thepin 21 is thus held, by the action of both springs in the U-shaped partof the second side 28b of the track. It will be apparent that the pushbutton 13 only returns part of the way back to the initial position.When the operating element is held in this position, the contact plate31 is held in a position equivalent to an electrically connectingposition of the strips on the member. This position of the parts isshown in FIGURE 3.

To switch oil, the push button 13 is again depressed and the pin '21moves out of the U of the second side 28b on the side adjacent to thethird side 280 until it reaches the third side under the influence ofthe spring 24 this movement ceasing when the pin lies in the junctionbetween the third and second sides of the track.

When the push button 13 is released, the pin 21 travels along the thirdside of the track, over the ramp and into the junction of the first andthird sides of the track, that is, the initial position.

The ramp eflectively prevents the pin from moving along the third sideinstead of the first side when the push button is again actuated. As theslidable member completes its movement, the contact plate 31 is again,of course moved to the initial position.

Having thus described my invention what I claim as new and desire tosecure by Letters Patent is:

1. An electrical switch comprising a manually operable pushbutton,biasing means urging the pushbutton in one direction, a pair of memberscomprising an arm connected to the pushbutton and an operating element,a body in which the members are mounted for sliding movement in mutuallytransverse directions, one of the members having a pin which isengageable in a track provided in the other member, the track being soarranged that movement of the arm will result in relatively transversemovement of said operating element, between two limiting positions, saidtrack being shaped to provide two retaining positions for the pincorresponding to the limiting positions of the operating element,movement of the pin from one of its positions to the other beingcontrolledin part by movement imparted by the pushbutton, and in part bymovement imparted by the resilient means and by further resilient meansurging the operating element in one direction, the operating-elementcarrying an electrical contact plate which is moved transversely of thedirection of travel of the pushbutton between one position in which itcan engage an electrical contact on an electrical printed circuit board,and a further position offset across the face of the board out ofcontact with the electrical contacts thereon.

2. An electrical switch according to claim 1 in which the operatingelement is formed with a track which is of generally triangular form,having first and third sides which are joined to a second side whichincludes a portion in which the pin can be releasably retained in aposition in which the contact plate can engage a contact on a printedcircuit board. 1

References Cited FOREIGN PATENTS 6/1913 Netherlands. 5/ 1964 GreatBritain.

